It plans to extend the initial "intensive enablement" release phase of both RHEL versions 4 and 5 from three years of earnest support to an even four years.

That means the versions will continue to receive minor releases about twice per year with new hardware updates, general bug fixing and additional features for another full swing around the sun.

Red Hat says it's extended the life cycle because OEMs have been asking that two generations of RHEL code get tuned for their new hardware at the same time.

At five years after their release, RHEL 4 and 5 will move to the "transition" phase where updates will be minor bug fixes made on a more flexible schedule.

Years six and seven are the last gasp before the final update release. Updates will be critical bug and security fixes only.

Let's look where that puts the current OSes:

RHEL 4 was released in 2005. That would have formally put it in "transition territory" at this time. But the OS now will get a reprieve from phase two at least until Q4 2009. The next update, RHEL 4.7 is planned for general release on July 21st.

Product marketing manager ANdrew Cathrow said 4.7 will include approximately 1,000 changes total. Among the list planned for July are:

A large number of fixes for Autofs

Samba fixes

An Infiniband update for OFED 1.3

Systemtap will have production support for kernel tracing

A clock-divider patch to reduce tick resolution to avoid time skew in VMware

Version 4.8 is scheduled for the first half of 2009.

RHEL 5 was released in 2007, so the OS will therefore continue to get regular phase 1 updates until 2011.

The next update of RHEL 5 will be version 5.3, scheduled for January 2009. Improvements include IBM Cell tweaks, additional power management, and support for 8TB memory on x86-64 systems.

The world of tomorrow

The next version of RHEL is currently in a planning and requirement phase. There's no fixed schedule for the next major release, according to Red Hat.

The Linux vendor wouldn't give away any specifics, but said it would focus on: systems management and provisioning, virtualization, power management, improved desktop support, storage snapshot and mirroring improvements, and a new scheduler. ®